Question mark instead of computer name in Finder

[Manic Harmonic]

Hi, I'm having this really odd bug that's been occurring since mountain lion. When I navigate to my volumes folder, instead of my Mac's name at the top it just shows a question mark. Everywhere else it's normal - the Sharing prefpane, sidebar, etc... Also when i cmd+click on it to bring up the little navigation menu the Mac name is blank. This happens on 2 of my machines. I have no idea when it started. Has anyone ever seen this before? Obviously it's only cosmetic but it's really annoying me. I will try to post a screenshot tomorrow.

 

[xgman]

I see this on occasion as well but usually when another app or process opens a finder window.